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  • 1
    ISSN: 1600-0560
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Immunohistochemical detection of certain low to intermediate molecular weight keratins often is impaired in routinely processed specimens due to masking of these antigens by formalin fixation. Despite standard enzymatic digestion, AE1:AE3 and CAM 5.2, two of the most currently utilized antikeratin antibody preparations, either stain weakly or fail to stain basal keratinocytes and tumors composed of basaloid keratinocytes in paraffin sections of formalin-fixed tissue.We present here our experience with the monoclonal antibody MNF116 which detects keratins 5, 6, 8, 17, and 19 (DAKO, Carpinteria, CA). We have studied 232 routinely-processed skin lesions with MNF116 and compared the staining with that of AE1:AE3 mixture or CAM 5.2. In normal skin, the staining achieved with MNF116 was particularly strong on the basal cells of the epidermis and adnexae. MNF116 was positive in all 154 epithelial tumors and negative in all but one (a leiomyosarcoma) of 78 mesenchymal and melanocytic tumors. AE1:AE3 mixture was positive in all but four poorly-differentiated squamous cell carcinomas and it was only weakly positive in most basal cell carcinomas. CAM 5.2 was positive in tumors of the sweat apparatus, Merkel cell carcinomas, metastatic carcinomas, and 5/15 basal cell carcinomas.We consider that, in routinely processed specimens, MNF116 is very useful and convenient for detection of cytokeratin expression in cutaneous lesions, and therefore helpful in the evaluation of tumors with small cells and other poorly differentiated neoplasms of the skin.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of cutaneous pathology 22 (1995), S. 0 
    ISSN: 1600-0560
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Dermatofibromas (DF) are common, benign skin tumors composed predominantly of cells having elongated nuclei and very scant cytoplasm (i.e., fibroblasts) and capillaries in a collagenous stroma. Some authors distinguish DF from benign fibrous histiocytomas (BFH), which are composed of cells with round to oval nuclei and abundant cytoplasm (i.e., histiocytes). In general, this group of tumors expresses factor XIIIa but not the antigen recognized by MAC 387. However, immunohistochemical differences specifically between DF and BFH have not been reported.We have studied the immunophenotype of 23 lesions having morphologic features predominantly either of DF (17 cases) or BFH (6 cases) using antibodies against desmin (muscle marker), α-smooth-muscle actin (muscle and myofibroblast marker), CD68 and HAM56 antigen (markers commonly expressed by macrophages, so called “histiocytic” markers), CD34 (a marker present in hematopoietic, vascular, and occasional dermal dendritic cells), and factor XIIIa (a transglutaminase present in many cells including dermal dendrocytes). Many spindle-shaped cells expressed a-smooth-muscle actin while many large, round cells expressed the histiocytic markers. However, most lesions expressed at least focally both α-smooth-muscle actin and “histiocytic” markers. Thus a clear-cut distinction between DF and BFH could not be made based on immunophenotype alone. Additionally, the prominent α-smooth-muscle actin immunoreactivity and desmin non-reactivity suggests myofibroblastic differentiation in the spindle-cell regions of these tumors, and indicates that expression of a-smooth-muscle actin cannot be used as definitive proof of muscle differentiation in spindle-cell tumors. We conclude that DF and BFH are not discrete entities, but represent polar expressions of one nosologic entity exhibiting both myofibroblastic and “histiocytic” differentiation.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1600-0560
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract:  Claudins are a family of transmembrane proteins involved in cell-to-cell adhesion and are believed to be the main component of tight junctions. Recent studies have suggested that some metastatic solid tumors lack claudin expression. It is unknown whether claudins play a role in cutaneous melanoma. Immunohistochemical studies were performed on tissue microarrays containing 19 benign melanocytic nevi (BN), 21 dysplastic nevi (DN), 23 primary malignant melanomas (MMs), and 31 metastatic melanomas (MMMs) using a polyclonal anti-claudin-1 antibody. Immunoreactivity in tumor cells and associated vessels was graded by intensity and by percentage of reactive cells. Normal epidermis served as internal control (3+ labeling). Cases with at least 2+ labeling in more than 25% of the cells were considered positive. Claudin-1 expression was present in 37% of BN, 24% of DN, 26% of MM, and 3.2% of MMM. Tumor-associated vessels showed the following results: 11 of 19 (58%) in BN, 14 of 21 (67%) in DN, 17 of 23 (74%) in MM, and 6 of 31 (19%) in MMM. A significant loss of expression was noted between MMM and all other lesions in tumor cells and associated vessels. There was no significant difference between BN, DN, and MM. Within primary melanomas, there was a significant correlation between expression of claudin in tumor cells and Clark level/Breslow thickness. Also significant was a decreased expression of claudin in tumor vessels of lesions with higher Breslow thickness or Clark level. These data suggest that loss of claudin-1 may play a significant role in the acquisition of metastatic phenotype in cutaneous melanoma.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Copenhagen : Munksgaard International Publishers
    Journal of cutaneous pathology 28 (2001), S. 0 
    ISSN: 1600-0560
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background: Malignant melanoma is notorious for the wide range of histologic patterns it can assume, among the least frequent of which is chondroid melamona.Methods: Two cases of primary chondroid melanoma of the distal lower extremity were studied. Tissue for light microscopy was fixed in formalin, embedded in paraffin, and processed routinely. In one case, transmission electron microscopy and immunohistochemical evaluation were performed.Results: Both cases exhibited melanoma in-situ, a conventional (non-chondroid) invasive component, and areas of chondroid differentiation, as confirmed by strongly positive staining with Alcian blue at pH 2.5 and Safranin O. Immunohistochemically, one case expressed S-100 protein and vimentin, and did not express gp100 (HMB-45), tyrosinase, MART-1, the Mel-5 antigen, the NKI/C3 antigen, CD45Ro, cytokeratin, or desmin. Electron microscopy of the chondroid component revealed occasional tumor cells with rare, membrane-bound, electron-dense organelles; the extracellular compartment showed amorphous ground substance consistent with cartilaginous differentiation.Conclusions: Chondroid change in the absence of osteogenic differentiation is extremely rare in malignant melanoma. Melanoma should be considered in the differential diagnosis of primary cutaneous neoplasms exhibiting cartilaginous differentiation.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Copenhagen : Munksgaard International Publishers
    Journal of cutaneous pathology 27 (2000), S. 0 
    ISSN: 1600-0560
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The embryologic histogenesis of cartilage is not well characterized. While cranial cartilage is believed to be derived from pluripotential precursor cells of the neural crest, chondrocytes found elsewhere in the body are thought to be derived from mesoderm. As such, soft tissue tumors with cartilaginous differentiation may be related to neural crest or mesoderm. Peripherin is an intermediate filament encoded on chromosome 12, involved in growth and development of the peripheral nervous system. Peripherin is apparently expressed exclusively in cells derived from the neural crest and neural tube. A group of six soft tissue tumor types was selected because they are either of controversial differentiation or cytogenetically related to chromosome 12. A total of 41 cases was evaluated with antibodies against the intermediate filament peripherin. A panel of neural and neuroendocrine differentiation markers was used in selected cases. Three of five extraskeletal myxoid chondrosarcomas showed strong cytoplasmic reactivity with anti-peripherin. No peripherin expression was noted in any of eleven epithelioid sarcomas, eight liposarcomas, seven conventional chondrosarcomas, four neurothekeomas, three alveolar soft part sarcomas, or three clear cell sarcomas. The finding of peripherin expression in some extraskeletal myxoid chondrosarcomas may suggest the ability of some tumors to demonstrate both neural and chondroid differentiation.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Oxford, UK : Munksgaard International Publishers
    Journal of cutaneous pathology 30 (2003), S. 0 
    ISSN: 1600-0560
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background:  Epithelioid sarcoma (ES) is a rare malignant soft tissue tumor of uncertain histogenesis that arises predominantly in the extremities of young adults. Immunohistochemically, the neoplastic cells are typically positive for vimentin, low molecular weight cytokeratin (CAM5.2) and epithelial membrane antigen (EMA).Method:  We examined eight cases of ES from seven different patients. All cases were studied with immunohistochemistry for EMA, CAM5.2 (keratin 8 and 18), 34BE12 (keratins 1, 5, 10 and 14/15), cytokeratins 7 and 20 (CK7, CK20), and CD34.Results:  The average patient age was 53 (range 43–76) and the male:female ratio was 5:2. The location was the upper extremity in five tumors, the lower extremity, the perineum, and the paraspinal soft tissue in one tumor each. All cases contained predominantly epithelioid cells, but spindle cells were also present in three cases. All cases contained areas of geographic necrosis. CAM5.2 was strongly positive in seven tumors and focally positive in one (8/8). EMA was diffusely positive in two cases and focally positive in five cases (7/8). CD34 was diffusely positive in 3/8 cases. 34BE12 was diffusely positive in one case and focally positive in two others (3/8). CK7 was diffusely positive in one case and focally positive in another (2/8). CK20 was negative in all cases (0/8). All cases tested were positive for vimentin (6/6), 2 cases were focally positive for HHF35 (2/5), and all cases tested were negative for S-100 protein (0/7).Conclusions:  In addition to the known immunoreactivity for CAM5.2 and EMA, there is positivity for CK7 and 34BE12 in a small proportion of cases. None of the cases expressed CK20. This immunophenotypic profile suggests that ES is more similar to carcinoma and synovial sarcoma than to other soft tissue tumors, and may be of diagnostic utility.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of cutaneous pathology 24 (1997), S. 0 
    ISSN: 1600-0560
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Cyclins are implicated in the induction and control of the cell cycle. Cyclin D1 regulates G1-phase progression by phosphorylation of the retinoblastoma protein (pRb). The Kaposi's sarcoma-associated herpesvirus/human herpesvirus 8 (KSHV) contains and transcribes an open reading frame with sequence similarities to cellular D-type cyclins. The KSHV-cyclin protein is associated with kinase activity capable of phosphorylating pRb in vitro. Here, we study for the first time the endogenous cyclin Dl and Rb protein expression in Kaposi's sarcoma (KS) tissue. Twenty-four consecutive biopsies of AIDS-related (n=21) and classical (n=3) KS were studied by immunohistochemistry with monoclonal antibodies against cyclin Dl and pRb. We detected cyclin Dl in 1 of 13 patch/plaque stage, in 4 of 5 nodular stage and in 3 of 6 visceral KS lesions. By Western blot analysis, this cellular cyclin Dl monoclonal antibody did not cross-react with the purified KSHV-cyclin protein. The pRb was consistently detected in 24 of 24 KS lesions. In summary, early KS lesions rarely have detectable expression of endogenous cyclin Dl. Advanced and disseminated KS lesions tend to have overexpression of endogenous cyclin Dl. Therefore, cellular cyclin Dl expression appears to correlate with tumor progression in KS. The endogenous cyclin Dl is antigenically distinct from the KSHV-cyclin homolog. The pRb, which may serve as a substrate for KSHV-cyclin, is found in all KS lesions examined.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Oxford, UK; Malden, USA : Munksgaard International Publishers
    Journal of cutaneous pathology 32 (2005), S. 0 
    ISSN: 1600-0560
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background:  Androgens have been implicated in androgenic alopecia as evidenced by the increased cutaneous expression of androgen receptor (AR), 5α-reductase, and decreased aromatase. Abnormalities of the AR-signal transduction pathway probably participate in the development of androgenic alopecia. ARA70/ELE1 is an AR coactivator with two isoforms, one full-length form (ARA70α/ELE1α), and an internally deleted form (ARA70β/ELE1β). We decided to examine the cutaneous expression of both isoforms in male androgenic alopecia.Methods:  Formalin-fixed, paraffin-embedded tissue sections from seven subjects with androgenic alopecia with matched punch biopsies from non-balding and balding areas were examined by in situ hybridization.Results:  Expression of at least one of the two probes for ARA70/ELE1 was present in all phases of the hair-growth cycle in all epithelial hair structures except for the inner root sheath. The dermal papilla and hair bulb expressed only the short (β) but not the long (α) form of ARA70/ELE1. In situ labeling for ARA70β/ELE1β was weaker in the dermal papilla of balding recipient areas than those from donor ones.Conclusions:  Our data further support that the hair growth is regulated by androgens. The differential expression pattern of ARA70/ELE1 suggests that this key androgen receptor coactivator is involved in androgenic alopecia.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Copenhagen : Munksgaard International Publishers
    Journal of cutaneous pathology 28 (2001), S. 0 
    ISSN: 1600-0560
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background: Epidermal necrosis in a neonate is an uncommon event with a variety of potential cases.Result: We report a case of intrauterine epidermal necrosis in a preterm infant, with death occurring soon after birth. The histopathology of the denuded skin revealed full-thickness epidermal necrosis and calcification within both the epidermis and follicular structures.Conclusion: We believe this represents the fourth reported case of lethal intrauterine epidermal necrosis and follicular calcification.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Oxford, UK : Munksgaard International Publishers
    Journal of cutaneous pathology 30 (2003), S. 0 
    ISSN: 1600-0560
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Type of Medium: Electronic Resource
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